1. Field of the Invention
The present invention relates to an RFID (radio frequency identification) tag having an identification information response function that wirelessly transmits tag identification information stored in the RFID tag in response to a predetermined wireless request, and a merchandise management system using such an RFID tag.
2. Description of the Related Art
In recent years, a great deal of attention has come to be focused on use of RFID tag systems in merchandise management. Such RFID tag systems allow non-contact reading of merchandise data stored in a tag. Further, such an RFID tag system allows simultaneous reading of merchandise data from multiple tags. Therefore, such RFID tag systems can significantly improve the efficiency of merchandise management in production, distribution, and sale.
However, RFID tags have the following problems. Specifically, unique tag identification information is assigned to each RFID tag, and RFID tags are configured to transmit the tag identification information in response to an external wireless request. As a result, because it is possible to identify an individual item of merchandise by reading tag identification information from an RFID tag attached to the item of merchandise, there is a risk that when and where the purchaser purchased the item may be known to other people. There is also a risk that a purchase history, credit card information, and other information stored in a database may be leaked to outsiders through the use of tag identification information. Further, there is also a possibility that, when an RFID tag is attached to clothes or a bag worn by a person, movement of that person may be tracked through the use of tag identification information. These problems are generally referred to as “privacy problems of RFID tags”, and represent a significant impediment to the full-scale introduction of RFID tags at the retail level.
In order to solve the above-described privacy problems of RFID tags, a technique has been proposed in which, at the time of purchasing an item of merchandise, a command known as a “Kill Command” is transmitted to an RFID tag from a reader/writer to invalidate the RFID tag.
a structure has been disclosed that a one-time password is held in a RAM (random access memory) that receives power supply from a power storage device, and the one-time password disappears when the power storage device is discharged. Although this structure can be effective in reducing the risk of unauthorized use of a one-time password, the above-described privacy problems are not solved because the tag identification information itself remains.
On the other hand, when an item of merchandise is returned after purchase, if it is possible to read tag identification information and merchandise data from an RFID tag attached to that item, it is easy to manage returned item, and it is possible to suitably respond to customer requests.
However, because the above-described invalidation technique invalidates an RFID tag at the same time as purchase of merchandise, it is impossible to read tag identification information from the RFID tag after completion of payment, such that it is no longer possible to easily manage returned merchandise.